Though shares have surged 57% in the past month, investors should curb their enthusiasm for the "slowly demolished" brand.

Many investors believe it can. That enthusiasm was fueled by two new developments. First, according to the official China Daily newspaper, China is considering ending a 12-year ban on the sale of videogame consoles, such as Sony's PlayStation. And Citigroup analyst Kota Ezawa upgraded the stock on Monday to Buy from Neutral arguing that Sony (ticker: SNE) is in for a...